Objective To analyze the relationship between onset of myocardial infarction(MI)to bivalent antibiotics therapy and outcome in elderly female MI patients.Methods One hundred and fourteen elderly MI patients admitted to our hospital from January 2016to January 2018were divided intoΔT≤188min group(n=57)andΔT＞188min group(n=57)according to the onset of MI to bivalent antibiotics therapy.The major adverse cardiac events(MACE),arrhythmia,angina pectoris,heart failure and death were compared between the two groups.Results MACE occurred in 44out of the 144MI patients included in this study.Of the 44MI patients,17died,6 were diagnosed with arrhythmia,16were diagnosed with angina pectoris,5were diagnosed with heart failure.The incidence of arrhythmia,heart failure and the mortality were significantly higher while the incidence of angina pectoris was significantly lower inΔT≤188min group than inΔT＞ 188min group(7.0％vs 3.5％,7.0％vs 1.8％,15.8％vs 14.0％,7.0％vs 21.1％,P＜0.05).Age,diabetes,ΔT,hyperlipidemia,hypertension and coronary artery disease were the independent influencing factors for the poor outcome in MI patients(P＜0.05,P＜0.01).Conclusion TheΔT should be shortened,the MI patients should be timely treated,the criminal blood vessels should be opened,and the ischemic myocardium should be saved in order to prevent the occurrence of severe cardiovascular events and reduce the mortality in elderly MI patients.

Objective To explore the value of ultra-large pitch Turbo Flash scan mode in the diagnosis of tracheal foreign body in infants.Methods The imaging data of 60 infants with foreign body in trachea confirmed by bronchus endoscopy were analyzed retrospectively. The 60 infants were equally divided into 2 groups according to the scanning time.For group A,the routine scan with the mode of CARE Dose 4D/CARE kV and pitch as 1.9 was performed.For group B,the scan with ultra-large pitch Turbo Flash model was performed.The scanning time,volume CT dose index (CTDIvol)and dose length product (DLP)of each patient were recorded in both groups and statistically analyzed.Results The scanning time,DLP and CTDIvol of group A and group B were statistically significant.CTDIvol and DLP of group B were significantly lower than those of group A (P＜0.05).The diagnostic accuracy of group A and B were 100%(30/30),respectively (P＞0.05).The foreign body display of group A and B were 100% (30/30),respectively (P＞0.05).Conclusion Ultra-large pitch Turbo Flash can be used to detect tracheal foreign body in infants.It can significantly reduce radiation dose,shorten examination time and obtain satisfactory image quality.

Objective To observe the therapeutic effect of low dose tolvaptan combined with furosemide in ederly patients with CHF and diuretic resistance (DR).Methods Eighty-five elderly patients with CHF and DR were divided into observation group (n=43) and control group (n=42).The patients in observation group were treated with cardiotonics and hypotensors plus oral tolvaptan (15 mg/d) combined with intravenous furosemide (40 mg/d).The therapeutic effect of low dose tolvaptan combined with furosemide was assessed.Results The average urinary volume was larger,and the LVEDV was significantly lower in two groups after treatment than before treatment (P＜0.05).The urinary volume was significantly larger while the LVEDV was significantly lower in observation group than in control group (2.89±0.87 L/d vs 2.43±0.49 L/d,P=0.01;103.6±21.5 ml vs 116.7±24.3 ml,P=0.01).The total effective rate was significantly higher in observation group than in control group (86.0％ vs 71.4％,P=0.01).Conclusion Low dose tolvaptan combined with furosemide can effectively improve the DR and therapeutic effect in elderly CHF patients,and is thus worth popularization in clinical practice.

Objective: To compare the value of two 3D imaging reconstruction methods for left atria and pulmonary vein on guiding the catheter ablation for atrial fibrillation (AF). Methods: From January 2014 to January 2017, a total of 100 drug refractory paroxysmal AF patients were divided into left atria direct angiography group (n=50), and indirect angiography group (n=50). 3D CARTO system was applied for mapping and guiding the ablation procedure. Patients assigned to direct angiography group were treated as follows: intraoperative puncture of atrial septum, inject contrast agent directly into the left atrium, conduct left atrial and pulmonary venous rotation angiography, reconstruct three-dimensional image, integrate the image into real-time X-ray system to facilitate circumferential pulmonary vein isolation. Patients assigned into the indirect angiography group were treated as follows: inject contrast agent through the right ventricle, conduct delayed rotation angiography of the left atria and pulmonary vein to guide circumferential pulmonary vein fixation and ablation. The left atrial and pulmonary venous image acquisition, the operation and X-ray exposure time, the success rate and the incidence of complication of the two groups were compared. The patients were followed up for 3-6 months. Results: General clinical characteristics of the two groups were similar(all P>0.05). Ablation was successful in all 100 patients. The operation time[(112.0±21.4)min vs. (134.0±24.3)min]and X-ray exposure time((10.7±4.7)min vs. (15.8±5.2)min)were significantly lower in direct angiography group than in indirect angiography group (both P<0.01). There was no significant difference between the two groups in the immediate (86%(43/50) vs. 82%(41/50), P=0.59) and short-term (76%(38/50) vs. 72%(36/50), P=0.65) success rate and complication rate (1 aneurysm in the direct angiography group, 1 pericardial tamponade in the indirect angiography group). In-hospital mortality was zero percent. Conclusion It is safe and effective method to guide the radiofrequency catheter ablation of paroxysmal atrial fibrillation by reconstruction 3D image of left atrium and pulmonary vein. Compared with indirect angiography group, direct angiography group can improve the imaging quality of left atrium and pulmonary vein, decrease the X-ray exposure time of the ablation procedure.

Objective To investigate the feasibility of chest examination using ultra-large pitch Turbo Flash in Force CT in preschool children without sedative.Methods A total of 90 preschool children evaluated as nervous or frightened were equally divided into 3 groups according to the scanning time.For group A,the routine scan with the mode of CARE Dose 4D/CARE kV was performed,and the sedative was used.For group B,the scan with ultra-large pitch Turbo Flash model and pitch as 3.0 was performed,and the sedative was used.For group C,the same scan mode as group B was performed but without sedative.The scanning time,radiation dose,image quality and the diagnostic efficiency were compared among 3 groups.Results There were no significant differences of the CT values of the aorta root,spinal posterior muscles and subcutaneous fat,the noise of the aorta root,SNR and CNR among 3 groups (all P＞0.05).Moreover,no significant differences of the subjective score of image quality in pulmonary window and mediastinum window images were found among 3 groups (both P＞0.05).The scanning time and radiation dose indexes (CT dose index volume [CTDIvo1],doselength product [DLP],effective dose [ED]) of group A were significantly higher than those of group B and group C (all P ＜0.05),while there were no significant differences between group B and group C (all P＞0.05).There were no significant differences between the CT diagnosis and clinical diagnosis results in all 3 groups (all P＞0.05).Conclusion It can shorten the scanning time and decrease the radiation dose by using the mode of ultra-large pitch Turbo Flash.And the satisfactory image quality can be obtained without sedative for nervous or frightened preschool children.

Objective To make spinal cor injury model of rabbit in order to investigate the feasibility and accuracy of diffusion tensor imaging in diagnosis of early ASCI. Methods In 30 Chinese rabbits ,24 rabbits were randomly selected as the experimental group and the other 6 as the control group. Allen′s technique were used to make moderateacute spinal cord injury in the experimental group. In the control group ,the operation only exposed the spinal membrane ,wihthout damage on the spinal cord. All rabbits were performed in routine MRI , DTI ,diffusion tensor tractography and post-processing. After the MRI scan ,the rabbit spinal cord was removed to have pathological examination at 1 ,3 ,5 ,7 days. Results The number of inflammatory cells and spinal motor neurons were closely correlated with FA values and ADC values. DTT images showed the spinal cord defects, curling and breaking. Conclusion The parameters of DTI (FA ,ADC) can reflect the pathological changes of acute spinal cord injury in early stage ,and therefore may be used as an routine evaluation method for clinical acute spinal cord injury.

Objective To investigate the diagnostic value and limitations of dual-energy virtual non-con-trast images of dual-source CT in common benign liver diseases. Methods Dual-source CT was performed on 226 upper abdomen pathogenesis patients. The conventional non-contrast (CNC) scan was performed with single-energy mode, the arterial phase and portal phase scans were performed with dual-energy mode. The virtual non-contrast (VNC) images were derived from the portal data using liver virtual non-contrast software. 117 patients with common benign liver diseases were retrospectively analyzed in CNC and VNC. The lesion detectability, effective radiation doses for single-energy mode and dual-energy mode were compared. Results Among 117 patients, there were 28 (73.6%) hemangiomas, 58 (85.3%) calcifications or stones in VNC, but the hemangiomas, calcifications or stones in CNC were 37 (97.3%) and 68 (100%), respectively. The hemangiomas, calcifications or stones in VNC and CNC were significantly different (P < 0.05). The detection of cyst and hepatic steatosis on VNC images were similar as CNC(P > 0.05). The CTDIvol, DLP and ED of dual-energy mode were obviously lower than those of single-energy mode (P < 0.05). Conclusion The detection of hemangiomas, calcifications or stones on VNC images is lower than CNC images. There is no difference in detecting cyst and hepatic steatosis. In addition, radiation dose will be reduced due to adopting VNC.VNC has potential clinical application value.

Objective To investigate the feasibility of T2 mapping in evaluating the composition of shoulder cartilage,and to quantitatively analyze T2 values of articular cartilage in healthy young volunteers.Methods Oblique coronal T2 mapping imaging with 8 echo was performed in bilateral shoulder of 16 young healthy volunteers.The pseudo-color map was obtained with post-processing.The shoulder joint cartilage was equally divided into the external,central and internal zones,and T2 values were measured quantitatively.T2 values in the external,central and internal zones were analyzed and compared.T2 values of cartilage between male and female volunteers as well as between left and right sides were analyzed.Resuits T2 values in the external,central and internal zones of cartilage were (38.67 ± 2.82)ms,(38.41 ± 2.52)ms and (36.49± 1.80)ms,respectively.The overall difference was statistically significant (F=7.789,P=0.001).T2 values in the external and central zones of cartilage were larger than those in the internal zone (both P＜0.05).T2 values of cartilagehad no significant differences between the left and right sides in the external,central and internal zones (all P＞0.05).There was significant difference of T2 value in the central zone (P＜0.05),while no significant difference of T2 value in the external and internal zones between different genders was found (both P＞0.05).Conclusion T2 mapping imaging can be used to evaluate the composition of shoulder cartilage changes.

Objective To investigate the performance of dual source CT scanning combined with low-tube-voltage iterative reconstruction (SAFIRE) for demonstrating coronary artery calcium plaques. Methods 70 patients with clinically suspected coronary atherosclerosis and with normal BMI received SAFIRE-3 or filtered back projection (FBP) for reconstruction after undergoing CT scans with tube voltage range of 100 kV. The CT images (average CT values, noise, SNR, and CNR) and subjective scores (number of calcium plaque, calcium plaque adjacent artifacts, and image quality) were compared between the two groups. Results The average CT value of the aortic root did not differ significantly between the two procedures for reconstruction (P > 0.05). Ob jective evaluation of the images (noise, SNR, and CNR) between the two groups was statistically significant (P < 0.05 for all comparisons), so was image subjective rating (number of calcium plaque and rate of calcium plaque edge)(P < 0.05 for all comparisons). SAFIRE-3 reconstruction was markedly superior to FBP reconstruc-tion. Conclusions Low kilovoltage combined with reconstruction of SAFIRE-3 can reduce calcium plaque adja-cent artifacts and enhance quality of images , which is better than FBP in displaying the morphology and adjacent conditions of calcified plaque; therefore it is worth popularizing.

Objective Based on the teeth in vitro skull specimen to investigate the feasibility and accuracy of CARE kV CT scan for reducing radiation dose. Methods Of eight fixed and preserved skull teeth were scanned repeatedly in groups of A, B, C. In expose factors of 100 kVp/150 mAs in conventional scanning of group A, open CARE Dose 4D scan of group B and CARE kV scan of group C. We assessed the radiation dose in the group A, B and C, the average CT values of the images, noise, SNR, CNR and subjective ratings. Results Three groups of actual scan tube current, tube voltage and radiation dose were statistically significant (P < 0.05). Compared with group A, the radiation dose in the group B was reduced by about 13.76% and 26.61%reduced in the C group. The average CT values of the images and the noise SNR, CNR and subjective ratings hasd no significant difference (P > 0.05). Conclusion CARE kV technology based on the use specimens tooth can reduce the radiation dose, protect image quality, and be consistent to the reports of previous researches.